American Contractor Database: How it was developed
According to staff at the Chicago History Museum, the American Contractor Database was developed entering data from the permit section of each issue of the American Contractor. Individuals manually typed data into key fields in a database; other individuals checked the accuracy of the data entry. There was a total of 15 years of issues reviewed (52 per year) for a total of 780 weekly issues reviewed. The Chicago History Museum has the photocopies of the individual sheets that were used in the data entry, so it is possible to check the accuracy of the database against the source document.
Although the microfilm permit ledgers prior to 1912 do not include a column for the architect, the name of the architect was furnished to the American Contractor by the building department at the time and the American Contractor printed it when it was furnished. Thus for the period 1898 to 1912 the American Contractor database can have architect name information when the microfilm of permit information developed from the building permit does not.
Though the database is a great tool, it has some limitations due to the manner in which it was set up. If for example you search on street name alone, you will get a long list. It will be arranged not in address order nor in strict chronological order. Rather it will be be arranged by the date of issue as expressed by month rather than year and not by the numerical equivalent of the month but rather by the first letter of the month as spelled out. Thus April will come before January. Also, the list may not be complete. The list may end for example in July. What happened to October and September?
A better approach is to use the combined street and issue date option at the bottom of the input screen. Each list will be arranged in street number order and it will be complete. All you have to do is change the year at the bottom to get a new list for that new year. Doing it this way may take slightly longer but the information will be complete.
Another limitation is that when two or more buildings were on the same permit, it may be that the address of only one was printed; thus the other addresses would not be found. Generally, this occurs only with homes built for developers, such as J.L. Cochran and B.F. Weber & Co, or the Weber-Kransz company. In such cases, one would have to search the actual microfilm records.